RESUMO
Polypyrrole (PPy) and polypyrrole/polyethylene glycol (PPy/PEG) implants synthesized by chemical, electro-chemical, and plasma polymerization methods were implanted into the injured spinal cord of rats to determine their effect on motor function recovery. Before implantation, the materials were characterized by infrared (IR) spectroscopy. An experimental model of traumatic spinal cord injury (TSCI) by complete transection at thoracic level 9, in rats was used. The polymer implants were inserted immediately after transection. Motor function recovery was evaluated once a week during 5 weeks using the Basso, Beattie and Bresnahan (BBB) motor scale. Histological evaluation was done at the end of the recovery evaluation period using hematoxylin/eosin stain. Results showed that animals implanted with polymers synthesized by plasma had a better integration into the nerve tissue, less inflammatory response and a better functional recovery than animals implanted with polymers synthesized by chemical or electrochemical methods.
En el presente trabajo se comparó el efecto de implantes poliméricos derivados del pirrol (polipirrol o PPy) y del copolímero polipirrol/polietilenglicol (PPy/PEG), obtenidos por diferentes métodos de síntesis: químico, electroquímico y polimerización por plasma con el propósito de determinar si el método de síntesis puede influir sobre el efecto que producen al ser implantados después de una lesión traumática de la médula espinal de ratas. Antes de realizar el implante, las características químicas y estructurales de los polímeros fueron analizadas por espectroscopia de infrarrojo (IR). Se utilizó un modelo experimental de lesión traumática de médula espinal (LTME) por sección completa en ratas. La LTME se realizó a nivel torácico 9 y el polímero fue implantado de inmediato en la zona de lesión. La recuperación de la función motora se evaluó mediante la escala Basso, Beattie y Bresnahan (BBB) una vez por semana durante 5 semanas. La evaluación histológica se realizó al término del seguimiento con la tinción de hematoxilina/eosina. Los resultados muestran que los animales implantados con polímeros sintetizados por plasma se integraron mejor al tejido nervioso, redujeron la respuesta inflamatoria y favorecieron una mayor recuperación funcional en comparación con los animales implantados con materiales sintetizados por métodos químicos o electroquímicos.
RESUMO
Currently, there are several techniques for modified cell culture surfaces under research to improve cell growth and adhesion. Recently, different methods have been used for surface coating, using biomolecules that enhance cell attachment and growth of nerve cells from spinal cord, such as the use of Poly-DL-Ornithine/Laminin. Plasma-polymerized pyrrole (PPy)-treated surfaces have showed improvement on surfaces biocompatibility with the cells in culture since they do not interfere with any of the biological cell functions. In the present work, we present a novel mouse nerve cell culture technique, using PPy-treated cell culture surfaces. A comparative study of cell survival using Poly-DL-Ornithine/Laminin-treated surfaces was performed. Our results of cell survival when compared with data already reported by other investigators, show that cells cultured on the PPy-modified surface increased survival up to 21 days when compared with Poly-DL-Ornithine/Laminin-coated culture, where 8 days cell survival was obtained. There were electrical and morphological differences in the nerve cells grown in the different surfaces. By comparing the peak ion currents of Poly-DL-Ornithine/Laminin-seeded cells for 8 days with cells grown for 21 days on PPy, an increase of 516% in the Na(+) current and 127% in K(+) currents in cells seeded on PPy were observed. Immunofluorescence techniques showed the presence of cell synapses and culture viability after 21 days. Our results then showed that PPy-modified surfaces are an alternative culture method that increases nerve cells survival from lumbar spinal cord cell culture by preserving its electrical and morphological features.
Assuntos
Técnicas de Cultura de Células/instrumentação , Neurônios/fisiologia , Pirróis/química , Medula Espinal/citologia , Potenciais de Ação , Animais , Sobrevivência Celular , Células Cultivadas , Meios de Cultura , Impedância Elétrica , Íons/metabolismo , Laminina , Vértebras Lombares , Potenciais da Membrana , Camundongos , Neurônios/citologia , Polimerização , Potássio/metabolismo , Sódio/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Sinapses/fisiologia , Fatores de TempoRESUMO
BACKGROUND: With a population of >112 million persons, all Mexicans are entitled to receive medical care by the state and more than half have limited access to healthcare. From January 1985 to March 2009, 40 renal transplants were performed from living donors with a high percentage of complications. In April 2009, a new Solid Organ Transplantation Program was started; herein, we present this enterprise to the international community and briefly present a perspective on the Mexican transplant situation. MATERIALS AND METHODS: We performed a retrospective chart review of kidney and liver transplant recipients from April 2009 to November 2011, including demographic features, immunosuppression, complications as well as initial and 1 month function. RESULTS: We performed 68 kidney (59 living and 9 deceased donors) and 5 liver transplants (cadaveric donors). The kidney transplant recipients were 73.5% males and showed an overall mean age of 29.77 years (range, 18-60). The donor mean age was 34.08 years. Mean recipient creatinine pretransplant was 13.32 mg/dL, while at day 5 it was 2.33 and at month one, 1.32 mg/dL. Five grafts were lost (7.3%): 4 due to death with a functioning graft and 1 due to acute pyelonephritis. Five patients experienced delayed graft function Basiliximab induction was required in all but one who received thymoglobulin owing to a high panel reactive antibody. Maintenance therapy included a calcineurin inhibitor, mycophenolate mofetil (MMF), and prednisone. Liver transplant recipients were 83.6% women. The etiologies were alcoholic cirrhosis (n = 2), primary billiary cirrhosis (n = 1) and hepatitis C virus infection (n = 2). Complications included: reperfusion syndrome (n = 1), convulsive crisis (medication; n = 1), acute respiratory distress syndrome (n = 1), and death (n = 1). Their Model for End-Stage Liver Disease scopes were 10-21. After basiliximab induction, they had maintenance therapy with tacrolimus, MMF, and steroids. The donor mean age was 26.2 years. All survivors show normal liver function tests currently. CONCLUSIONS: From 1985 to 2009, 40 kidney transplants were performed, with multiple complications including donor deaths. Our current results were comparable to international standards, with <15% complication rate.
Assuntos
Hospitais Gerais/organização & administração , Transplante de Órgãos , Adolescente , Adulto , Países em Desenvolvimento , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Adulto JovemRESUMO
Polymers synthesized by plasma derived from pyrrole have been recently implanted in rats with spinal cord injuries (SCI) using a complete section model; the polymers contribute to the functional recovery after the injury. In this work, the SCI in rats was studied using noninvasive techniques such as magnetic resonance imaging (MRI). Also computerized axial tomography taken chronologically with and without polymeric implants. 3D reconstructions were used to follow the structural arrangement, the location of the implant and the formation of cysts. MRI shows a clear differentiation between white and gray matter, the implanted material and cysts due to secondary damage after the injury.
Polímeros sintetizados por plasma derivados del pirrol, han sido implantados en ratas con lesión de médula espinal (LME) usando un modelo de lesión por sección completa; los polímeros contribuyen a la recuperación funcional después de la lesión. En este trabajo, la LME se estudió usando técnicas no invasivas como imágenes por resonancia magnética (IRM) y tomografía axial computarizada tomada cronológicamente en sujetos con y sin implante polimérico. Se usaron reconstrucciones 3D para seguir el arreglo estructural, la localización del implante y la formación de quistes. Las IRM muestran una clara diferenciación entre materia gris, materia blanca, material implantado y quistes formados debido a los mecanismos de daño secundario después de la lesión.
RESUMO
The aim of this work is to implement a biological model of neuromuscular junctions to study the mechanisms involved in intra and inter cellular processes using cell co-cultures. To optimize growth and development of the neuromuscular junction, cells were seeded on plasma polymerized pyrrole which has proven suitable for other types of cell cultures. The cell lines used were motor neuron NG108-15 and skeletal muscle C2C12. Cells were evaluated according to their morphology and electrophysiological characteristics. To observe the expression of specific proteins of the nerve synapse, immunocytochemical techniques were applied using dying antibodies. Proteins localized in nerve terminals were dyed and imaged by fluorescence microscopy. Images of cell co-cultures showed the formation of neuromuscular junctions. The preparation of neuromuscular junctions described in this work will allow the study of the mechanisms involved in their functions.
El objetivo de este trabajo es implementar un modelo biológico de unión neuromuscular para el estudio de los mecanismos involucrados en los procesos intra e intercelulares empleando co-cultivos celulares. Con el fin de optimizar el crecimiento y desarrollo de las uniones neuromusculares, las células se cultivaron sobre superficies de polipirrol obtenidas mediante polimerización por plasma que han mostrado ser adecuadas en otros tipos de cultivos celulares. Las líneas celulares que se emplearon fueron los modelos de motoneurona NG108-15 y muscular C2C12. Las células se evaluaron de acuerdo a su morfología y características electrofisiológicas. Para observar la expresión de proteínas clave de la sinapsis, se aplicaron técnicas inmunocitoquímicas utilizando anticuerpos específicos para la marcación de proteínas localizadas en las terminales nerviosas adquiriendo imágenes con microscopía de fluorescencia. Las imágenes de los co-cultivos celulares mostraron la formación de uniones neuromusculares. El método de preparación de uniones neuromusculares que se describe en este trabajo permitirá estudiar los mecanismos involucrados en sus funciones.
RESUMO
The adaptation of the technique for measuring the contact angle (CA) in order to follow the changes of sludge settleability of a denitrifying sludge surface is described. Denitrifying sludge was continuously fed into an upflow anaerobic sludge blanket (UASB) reactor with acetate and nitrate. The loss of settleability in the sludge was induced by decreasing the hydraulic residence time (HRT) from 1 d to 0.125 d. CA was measured with air and nitrogen bubbles. A comparison between sludge volume index (SVI) and the CA and their correlation with sludge settleability was carried out. Results showed that CA method had a high correlation with sludge settleability. Moreover the CA method showed to be simpler and less time consuming than the SVI method.